using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using System.Text.Json;
using JGSY.CMS.LowCode.Platform.Application.DTOs;
using JGSY.CMS.LowCode.Platform.Application.Interfaces;
using JGSY.CMS.LowCode.Platform.Domain.Entities;
using JGSY.CMS.LowCode.Platform.Infrastructure.CmsDbContext;

namespace JGSY.CMS.LowCode.Platform.Application.Services
{
    /// <summary>
    /// 租户数据管理服务实现
    /// </summary>
    public class TenantDataManagementService : ITenantDataManagementService
    {
        private readonly LowCodeDbContext _dbContext;
        private readonly ILogger<TenantDataManagementService> _logger;

        public TenantDataManagementService(
            LowCodeDbContext dbContext,
            ILogger<TenantDataManagementService> logger)
        {
            _dbContext = dbContext;
            _logger = logger;
        }

        #region 数据备份

        /// <summary>
        /// 创建数据备份
        /// </summary>
        public async Task<object> CreateBackupAsync(Guid tenantId, object request)
        {
            try
            {
                _logger.LogInformation("Creating backup for tenant {TenantId}", tenantId);

                var backup = new TenantDataBackup
                {
                    TenantId = tenantId.ToString(),
                    BackupName = $"Backup_{DateTime.UtcNow:yyyyMMdd_HHmmss}",
                    BackupType = "full",
                    Status = "pending",
                    StartedAt = DateTime.UtcNow,
                    TriggerType = "manual"
                };

                _dbContext.Set<TenantDataBackup>().Add(backup);
                await _dbContext.SaveChangesAsync();

                return new
                {
                    BackupId = backup.Id,
                    Status = backup.Status,
                    StartedAt = backup.StartedAt,
                    Message = "Backup job created successfully"
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to create backup for tenant {TenantId}", tenantId);
                throw;
            }
        }

        /// <summary>
        /// 获取租户的所有备份
        /// </summary>
        public async Task<List<object>> GetBackupsAsync(Guid tenantId)
        {
            var backups = await _dbContext.Set<TenantDataBackup>()
                .Where(b => b.TenantId == tenantId.ToString())
                .OrderByDescending(b => b.StartedAt)
                .Select(b => new
                {
                    b.Id,
                    b.BackupName,
                    b.BackupType,
                    b.Status,
                    b.BackupSizeBytes,
                    b.StartedAt,
                    b.CompletedAt,
                    b.ExpiresAt,
                    DurationMinutes = b.DurationMinutes,
                    BackupSizeMB = b.BackupSizeMB,
                    IsExpired = b.IsExpired
                })
                .ToListAsync();

            return backups.Cast<object>().ToList();
        }

        /// <summary>
        /// 获取指定备份详情
        /// </summary>
        public async Task<object> GetBackupAsync(Guid backupId)
        {
            // 将Guid转换为long（假设我们使用的是自增ID的映射策略）
            if (!long.TryParse(backupId.ToString("N")[..16], System.Globalization.NumberStyles.HexNumber, null, out long id))
            {
                id = Math.Abs(backupId.GetHashCode());
            }

            var backup = await _dbContext.Set<TenantDataBackup>()
                .FirstOrDefaultAsync(b => b.Id == id);

            if (backup == null)
                throw new KeyNotFoundException($"Backup {backupId} not found");

            return new
            {
                backup.Id,
                backup.TenantId,
                backup.BackupName,
                backup.BackupType,
                backup.Status,
                backup.BackupSizeBytes,
                backup.FilePath,
                backup.StorageLocation,
                backup.StartedAt,
                backup.CompletedAt,
                backup.ExpiresAt,
                backup.ErrorMessage,
                backup.ChecksumMD5,
                backup.ChecksumSHA256,
                backup.IsEncrypted,
                backup.ValidationStatus,
                DurationMinutes = backup.DurationMinutes,
                BackupSizeMB = backup.BackupSizeMB,
                IsExpired = backup.IsExpired,
                IsValidated = backup.IsValidated
            };
        }

        /// <summary>
        /// 删除备份
        /// </summary>
        public async Task DeleteBackupAsync(Guid backupId)
        {
            if (!long.TryParse(backupId.ToString("N")[..16], System.Globalization.NumberStyles.HexNumber, null, out long id))
            {
                id = Math.Abs(backupId.GetHashCode());
            }

            var backup = await _dbContext.Set<TenantDataBackup>()
                .FirstOrDefaultAsync(b => b.Id == id);

            if (backup != null)
            {
                _dbContext.Set<TenantDataBackup>().Remove(backup);
                await _dbContext.SaveChangesAsync();
                _logger.LogInformation("Backup {BackupId} deleted successfully", backupId);
            }
        }

        /// <summary>
        /// 下载备份文件
        /// </summary>
        public async Task<string> DownloadBackupAsync(Guid backupId)
        {
            if (!long.TryParse(backupId.ToString("N")[..16], System.Globalization.NumberStyles.HexNumber, null, out long id))
            {
                id = Math.Abs(backupId.GetHashCode());
            }

            var backup = await _dbContext.Set<TenantDataBackup>()
                .FirstOrDefaultAsync(b => b.Id == id);

            if (backup == null)
                throw new KeyNotFoundException($"Backup {backupId} not found");

            if (string.IsNullOrEmpty(backup.FilePath))
                throw new InvalidOperationException("Backup file path not available");

            return backup.FilePath;
        }

        #endregion

        #region 数据恢复

        /// <summary>
        /// 从备份恢复数据
        /// </summary>
        public Task<object> RestoreFromBackupAsync(Guid tenantId, Guid backupId, object request)
        {
            try
            {
                _logger.LogInformation("Starting restore from backup {BackupId} for tenant {TenantId}", backupId, tenantId);

                var result = new
                {
                    JobId = Guid.NewGuid(),
                    Status = "pending",
                    TenantId = tenantId,
                    BackupId = backupId,
                    StartedAt = DateTime.UtcNow,
                    Message = "Restore job started successfully"
                };
                return Task.FromResult<object>(result);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to start restore from backup {BackupId} for tenant {TenantId}", backupId, tenantId);
                throw;
            }
        }

        public async Task<object> GetRestoreJobAsync(Guid jobId)
        {
            await Task.Delay(1); // 模拟异步操作
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Restore job completed successfully"
            };
        }

        public async Task<List<object>> GetRestoreJobsAsync(Guid tenantId)
        {
            await Task.Delay(1); // 模拟异步操作
            return new List<object>();
        }

        public async Task CancelRestoreJobAsync(Guid jobId)
        {
            _logger.LogInformation("Cancelling restore job {JobId}", jobId);
            await Task.Delay(1); // 模拟异步操作
        }

        #endregion

        #region 数据迁移

        public async Task<object> CreateMigrationJobAsync(Guid sourceTenantId, Guid targetTenantId, object request)
        {
            try
            {
                _logger.LogInformation("Creating migration job from {SourceTenantId} to {TargetTenantId}", sourceTenantId, targetTenantId);

                var migration = new TenantDataMigration
                {
                    TenantId = sourceTenantId.ToString(),
                    TargetTenantId = targetTenantId.ToString(),
                    MigrationName = $"Migration_{DateTime.UtcNow:yyyyMMdd_HHmmss}",
                    MigrationType = "transfer",
                    Status = "pending",
                    StartedAt = DateTime.UtcNow
                };

                _dbContext.Set<TenantDataMigration>().Add(migration);
                await _dbContext.SaveChangesAsync();

                return new
                {
                    JobId = migration.Id,
                    Status = migration.Status,
                    StartedAt = migration.StartedAt,
                    Message = "Migration job created successfully"
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to create migration job from {SourceTenantId} to {TargetTenantId}", sourceTenantId, targetTenantId);
                throw;
            }
        }

        public async Task<object> GetMigrationJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Migration job completed successfully"
            };
        }

        public async Task<List<object>> GetMigrationJobsAsync(Guid tenantId)
        {
            var migrations = await _dbContext.Set<TenantDataMigration>()
                .Where(m => m.TenantId == tenantId.ToString())
                .OrderByDescending(m => m.StartedAt)
                .Select(m => new
                {
                    m.Id,
                    m.MigrationName,
                    m.MigrationType,
                    m.Status,
                    m.StartedAt,
                    m.CompletedAt,
                    m.TargetTenantId
                })
                .ToListAsync();

            return migrations.Cast<object>().ToList();
        }

        public async Task CancelMigrationJobAsync(Guid jobId)
        {
            _logger.LogInformation("Cancelling migration job {JobId}", jobId);
            await Task.Delay(1);
        }

        #endregion

        #region 数据导入导出

        public Task<object> CreateExportJobAsync(Guid tenantId, object request)
        {
            _logger.LogInformation("Creating export job for tenant {TenantId}", tenantId);
            var result = new
            {
                JobId = Guid.NewGuid(),
                Status = "pending",
                TenantId = tenantId,
                StartedAt = DateTime.UtcNow,
                Message = "Export job created successfully"
            };
            return Task.FromResult<object>(result);
        }

        public Task<object> CreateImportJobAsync(Guid tenantId, object request)
        {
            _logger.LogInformation("Creating import job for tenant {TenantId}", tenantId);
            var result = new
            {
                JobId = Guid.NewGuid(),
                Status = "pending",
                TenantId = tenantId,
                StartedAt = DateTime.UtcNow,
                Message = "Import job created successfully"
            };
            return Task.FromResult<object>(result);
        }

        public async Task<object> GetExportJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Export job completed successfully"
            };
        }

        public async Task<object> GetImportJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Import job completed successfully"
            };
        }

        public async Task<string> DownloadExportFileAsync(Guid jobId)
        {
            await Task.Delay(1);
            return $"/exports/{jobId}.zip";
        }

        #endregion

        #region 数据清理

        public async Task<object> CreateCleanupJobAsync(Guid tenantId, object request)
        {
            try
            {
                _logger.LogInformation("Creating cleanup job for tenant {TenantId}", tenantId);

                var cleanup = new TenantDataCleanup
                {
                    TenantId = tenantId.ToString(),
                    CleanupName = $"Cleanup_{DateTime.UtcNow:yyyyMMdd_HHmmss}",
                    CleanupType = "archive",
                    Status = "pending",
                    StartedAt = DateTime.UtcNow
                };

                _dbContext.Set<TenantDataCleanup>().Add(cleanup);
                await _dbContext.SaveChangesAsync();

                return new
                {
                    JobId = cleanup.Id,
                    Status = cleanup.Status,
                    StartedAt = cleanup.StartedAt,
                    Message = "Cleanup job created successfully"
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to create cleanup job for tenant {TenantId}", tenantId);
                throw;
            }
        }

        public async Task<List<object>> GetCleanupJobsAsync(Guid tenantId)
        {
            var cleanups = await _dbContext.Set<TenantDataCleanup>()
                .Where(c => c.TenantId == tenantId.ToString())
                .OrderByDescending(c => c.StartedAt)
                .Select(c => new
                {
                    c.Id,
                    c.CleanupName,
                    c.CleanupType,
                    c.Status,
                    c.StartedAt,
                    c.CompletedAt
                })
                .ToListAsync();

            return cleanups.Cast<object>().ToList();
        }

        public async Task<object> GetCleanupJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Cleanup job completed successfully"
            };
        }

        public async Task CancelCleanupJobAsync(Guid jobId)
        {
            _logger.LogInformation("Cancelling cleanup job {JobId}", jobId);
            await Task.Delay(1);
        }

        #endregion

        #region 数据统计

        public async Task<object> GetDataStatisticsAsync(Guid tenantId)
        {
            try
            {
                // 模拟统计数据
                return new
                {
                    TenantId = tenantId,
                    TotalSizeBytes = 1024 * 1024 * 100, // 100MB
                    TotalRecords = 10000,
                    TableCount = 25,
                    LastUpdated = DateTime.UtcNow,
                    BackupCount = await _dbContext.Set<TenantDataBackup>()
                        .CountAsync(b => b.TenantId == tenantId.ToString()),
                    MigrationCount = await _dbContext.Set<TenantDataMigration>()
                        .CountAsync(m => m.TenantId == tenantId.ToString()),
                    CleanupCount = await _dbContext.Set<TenantDataCleanup>()
                        .CountAsync(c => c.TenantId == tenantId.ToString())
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to get data statistics for tenant {TenantId}", tenantId);
                throw;
            }
        }

        public async Task<object> GetDataGrowthAnalysisAsync(Guid tenantId, DateTime startDate, DateTime endDate)
        {
            await Task.Delay(1);
            return new
            {
                TenantId = tenantId,
                StartDate = startDate,
                EndDate = endDate,
                GrowthRate = "5.2%",
                TotalGrowthBytes = 1024 * 1024 * 10, // 10MB
                DailyAverage = 1024 * 1024, // 1MB per day
                Trend = "increasing"
            };
        }

        public async Task<List<object>> GetDataSizeByTableAsync(Guid tenantId)
        {
            await Task.Delay(1);
            return new List<object>
            {
                new { TableName = "users", SizeBytes = 1024 * 1024 * 20, RecordCount = 1000 },
                new { TableName = "articles", SizeBytes = 1024 * 1024 * 50, RecordCount = 5000 },
                new { TableName = "categories", SizeBytes = 1024 * 1024 * 5, RecordCount = 100 }
            };
        }

        #endregion

        #region 数据归档

        public async Task<object> CreateArchiveJobAsync(Guid tenantId, object request)
        {
            _logger.LogInformation("Creating archive job for tenant {TenantId}", tenantId);
            return await Task.Run(() => new
            {
                JobId = Guid.NewGuid(),
                Status = "pending",
                TenantId = tenantId,
                StartedAt = DateTime.UtcNow,
                Message = "Archive job created successfully"
            });
        }

        public async Task<List<object>> GetArchiveJobsAsync(Guid tenantId)
        {
            await Task.Delay(1);
            return new List<object>();
        }

        public async Task<object> GetArchiveJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Archive job completed successfully"
            };
        }

        public async Task CancelArchiveJobAsync(Guid jobId)
        {
            _logger.LogInformation("Cancelling archive job {JobId}", jobId);
            await Task.Delay(1);
        }

        #endregion

        #region 数据验证

        public async Task<object> CreateValidationJobAsync(Guid tenantId, object request)
        {
            _logger.LogInformation("Creating validation job for tenant {TenantId}", tenantId);
            return await Task.Run(() =>new
                {
                    JobId = Guid.NewGuid(),
                    Status = "pending",
                    TenantId = tenantId,
                    StartedAt = DateTime.UtcNow,
                    Message = "Validation job created successfully"
                });
        }

        public async Task<List<object>> GetValidationJobsAsync(Guid tenantId)
        {
            await Task.Delay(1);
            return new List<object>();
        }

        public async Task<object> GetValidationJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                IssueCount = 0,
                Message = "Validation job completed successfully"
            };
        }

        public async Task<List<object>> GetValidationIssuesAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new List<object>();
        }

        #endregion

        #region 数据同步

        public async Task<object> CreateSyncJobAsync(Guid tenantId, object request)
        {
            _logger.LogInformation("Creating sync job for tenant {TenantId}", tenantId);
            await Task.Delay(1); // 模拟异步操作
            
            return new
            {
                JobId = Guid.NewGuid(),
                Status = "pending",
                TenantId = tenantId,
                StartedAt = DateTime.UtcNow,
                Message = "Sync job created successfully"
            };
        }

        public async Task<List<object>> GetSyncJobsAsync(Guid tenantId)
        {
            await Task.Delay(1);
            return new List<object>();
        }

        public async Task<object> GetSyncJobAsync(Guid jobId)
        {
            await Task.Delay(1);
            return new
            {
                JobId = jobId,
                Status = "completed",
                Progress = 100,
                Message = "Sync job completed successfully"
            };
        }

        public async Task CancelSyncJobAsync(Guid jobId)
        {
            _logger.LogInformation("Cancelling sync job {JobId}", jobId);
            await Task.Delay(1);
        }

        #endregion

        #region 批量操作

        public async Task<List<object>> GetAllJobsAsync(Guid tenantId, string? jobType = null)
        {
            var jobs = new List<object>();

            // 添加备份作业
            var backups = await GetBackupsAsync(tenantId);
            jobs.AddRange(backups.Select(b => new { Type = "backup", Job = b }));

            // 添加迁移作业
            var migrations = await GetMigrationJobsAsync(tenantId);
            jobs.AddRange(migrations.Select(m => new { Type = "migration", Job = m }));

            // 添加清理作业
            var cleanups = await GetCleanupJobsAsync(tenantId);
            jobs.AddRange(cleanups.Select(c => new { Type = "cleanup", Job = c }));

            if (!string.IsNullOrEmpty(jobType))
            {
                jobs = jobs.Where(j => ((dynamic)j).Type == jobType).ToList();
            }

            return jobs;
        }

        public async Task CancelAllJobsAsync(Guid tenantId, string? jobType = null)
        {
            _logger.LogInformation("Cancelling all jobs for tenant {TenantId}, type: {JobType}", tenantId, jobType ?? "all");
            await Task.Delay(1); // 模拟异步操作
        }

        #endregion
    }
}
